Films like Martin Scorsese’s “Kundun” and Bernardo Bertolucci’s “Little Buddha” acquainted American audiences with the Tibetan Buddhist belief that the souls of great lamas are reincarnated in newborns, who must be identified and then schooled to fulfill their destinies as spiritual teachers. But what happens if a designated youngster rejects that call?

Jennifer Fox’s remarkable documentary “My Reincarnation” follows one such individual over the course of 20 years, only to find that destiny will have its way. In the late 1980s Ms. Fox (“An American Love Story”) served as the secretary of Chogyal Namkhai Norbu, a master of the Dzogchen tradition of Buddhism who has lived in Italy for a half-century and built a teaching and spiritual center there, and was permitted to film it. His Westernized son, Yeshi, has been acknowledged since he was 5 to be the reincarnation of his father’s uncle Khyentse, a great Dzogchen master himself. Yeshi, though, in his late teens, strongly rebuffs a life expected by others, including his father, to whom he does not feel especially close.

Ms. Fox returned 13 years later, filming off and on until about 2009. Yeshi — now in his 30s with a family of his own and a career in information-technology management — has, through dreams and visions, a slow but insistent spiritual awakening. When he finally travels to Tibet, he is met by hundreds of Khyentse’s followers, some of whom have hungered for his arrival for decades.

These are among the film’s most successful scenes; others include those outlining the casual, ordinary home life of a Tibetan master. Still, an awful lot is packed into a bit more than 80 minutes — Yeshi’s journey, his father’s history, the growth of the Dzogchen movement, samples of Buddhist teachings — and the parts don’t always cohere. So the father-and-son story wins out.

Especially in the early footage, Chogyal Namkhai Norbu is an engaging, charismatic figure; by the end, Yeshi is finding his own footing, able to relate to a young, wired-in audience. “My Reincarnation” makes a pretty strong case: when the family business is enlightenment, listen to your dad.